Windscreen wiper arrangement

ABSTRACT

The invention is based on a windshield wiper system having at least one wiper bearing that is secured to a body of a vehicle via at least one bracing region ( 20 ). It is proposed that the bearing housing ( 10 ) of the wiper bearing has three bracing regions ( 20, 22, 24 ), specifically a first bracing region ( 20 ), which includes a longitudinal axis ( 18 ) of the bearing housing ( 10 ) and is provided on an end that is oriented toward a wiper, and a second bracing region ( 22 ) and third bracing region ( 24 ), which are provided axially offset toward the other end relative to the first bracing region and are disposed approximately diametrically opposite one another with regard to the longitudinal axis ( 18 ) of the bearing housing ( 10 ).

BACKGROUND OF THE INVENTION

Windshield wiper systems for motor vehicles are as a rule secured to thebody of a motor vehicle with a wiper carrier, that is, a so-calledmounting plate or tubular mount—if the wiper carrier also comprisestubes. The mounting plate carries a wiper drive mechanism with a wipermotor and a gear, built onto it, whose power takeoff shaft as a rule viaa crank and connecting rods drives cranks which are solidly connected toa drive shaft for each windshield wiper. The mounting plate determinesthe position of the wiper motor relative to wiper bearings, in which thedrive shafts of the windshield wipers are supported. It also absorbs theforces dictated by the wiper drive mechanism.

The bearing housings of the wiper bearings are fastened or formed ontothe ends of the mounting plate. The mounting plate is secured directlyto a vehicle body via the bearing housing, or via fastening eyelets thatare formed onto the bearing housing, the mounting plate, and/or themotor mounting plate. In each case, however, additional components arerequired in order to connect the windshield wiper system to the vehiclebody in a largely vibration-free, torsion- resistant way.

If the mounting plates are put together from many components, this meansnumerous interfaces with attendant tolerances. An imprecise adjustmentof the angular locations and positions of the wiper bearings relative tothe wiper motor and/or the wiper blade makes the outcome of wipingworse. To achieve adequate quality of the connections, the components tobe mounted must have high precision, which in turn increases theproduction cost. In addition, the numerous mounting steps increasemounting costs.

For this reason, wiper bearings with fastening screws are also screweddirectly to the firewall of the vehicle body or are received inretaining angle brackets that are welded to the firewall. The firewallmay be produced from sheet metal by a deep-drawing process. Firewallswith a continuous-casting profile are also known as a support element.

From German Utility Model DE-GM 74 34 119, a tubular mount is known thatis made from a square tube to which a plate acting as the motor mountingplate is welded. One wiper bearing is fixed to each end of the squaretube. Such tubular mounts or tubular frame systems are highly stabledespite their lightweight construction. For cost reasons, the goal is astraight carrier tube that requires no prior bending operation. Theparts serving to secure the wiper bearing, however, must be designed insuch a way that sufficient resistance is presented to engaging forces.For this reason, they must have a certain strength, which meansincreased consumption of material.

Another tubular mount is known from German Patent DE 29 20 899 C2, inwhich tubular stubs are thrust with suitable attachments into the hollowprofile of the mounting plate tube. At least some of the attachmentsrest on the walls of the mounting plate tube and have at least onerecess, into which portions of the mounting plate tube are pressed, inorder to form a positive-engagement connection between the mountingplate tube and the tubular stub. The wiper bearings are disposed inthese tubular stubs. Compared with screw connections, the number ofparts is reduced, but the joining process still requires numerousprefabricated individual parts with many production steps. This makesstockkeeping and logistics more expensive. Furthermore, the solidattachments, despite the recesses, are quite heavy.

SUMMARY OF THE INVENTION

According to the invention, the bearing housing of the wiper bearing hasthree bracing regions, specifically a first bracing region, whichincludes a longitudinal axis of the bearing housing and is provided onan end that is oriented toward a wiper. A second and third bracingregion are provided axially offset toward the other end relative to thefirst bracing region and are disposed approximately diametricallyopposite one another with regard to the longitudinal axis (18) of thebearing housing (10). The first bracing region is formed by a flange,while the second and third bracing regions are expediently embodied asplug-in feet, which are connected to the bearing housing and engagepockets on the retaining device.

A drive shaft for a wiper is supported in the bearing housing of thewiper bearing and is connected to a crank of an attached coupling gear.The forces and moments exerted on the wiper bearing by the drivemechanism are absorbed reliably and precisely by the three bracingregions and are conducted over a short path into the vehicle body,without the need to fear vibration and deformation that could impair thewiping quality.

In general, it is possible to dispense with a special mounting plate,especially if the firewall is produced as a die-cast part, onto which aretaining angle bracket with a receiving opening an d pockets forreceiving plug-in feet are formed, which are connected to the bearinghousing. This reduces the otherwise high number of parts. The mountingexpense is also lessened, because the bearing housing is inserted frombelow through the receiving opening, and at the same time the plug-infeet slide into the pockets. The position is then fixed by means of ascrew nut, which is screwed onto an integrally cast thread on thebearing housing and presses a flange of the bearing housing against theretaining angle bracket.

The reaction force to the contact force of the wiper blade on thevehicle window, which acts via the drive shaft on the bearing housingand engages it upward approximately parallel to the longitudinal axisacts as a pressure force on the end of the bearing housing toward thelever gear. It is absorbed in the wiper blade by the bracing regions andreinforces the retention force of. the screw connection. The force thatis introduced through the moment of the wiper motor via the cranks isalso located within a support triangle that is formed by the threebracing regions; the support regions have relatively great spacings fromone another. This type of bracing is quite stable and produces anoptimal, uniform transmission of force to the vehicle body.

Expediently, uncoupling elements comprising a rubber—elastic materialare provided both between the bearing housing and the retaining anglebracket and on the plug-in feet. These uncoupling elements preventshifting noises of the wiper blades and motor noises from beingtransmitted to the vehicle body via the wiper bearing. The uncouplingelements at the same time prevent contact erosion, which could occur ifin the case of metal materials for the bearing housing and magnesium ormagnesium alloys are used for the firewall.

The uncoupling elements are reliably easy to mount as a result, and inparticular the uncoupling element on the retaining angle bracket can beembodied in one piece with it and can have a circumferential groove, sothat even upon preassembly it can be snapped into the receiving openingof the retaining angle bracket. In a two-part version, one part isinserted with an attachment into the retaining angle bracket, while asecond associated part is placed on the flange of the bearing housing.The uncoupling elements between the plug-in feet and the pockets haverecesses, with which they are slipped onto the plug-in feet. Asimplified variant provides for extrusion of the uncoupling elementsonto the plug-in feet, thus dispensing with mounting them.

According to the invention, the bearing housing of the wiper bearing andthe firewall of the vehicle body are made from die-cast material, andretaining elements are integrally cast or extruded onto both parts. Diecasting produces the best results with regard to dimensional precision,surface quality, and slimness of the castings. Very complex die-castparts with various wall thicknesses can be made. As a rule, nopostmachining whatever is needed, resulting in low production costs.Finally, die-cast parts contribute to reducing the weight of thecomponent.

Further advantages will become apparent from the ensuing description ofthe drawings. In the drawings, exemplary embodiments of the inventionare shown. The drawing, specification and claims include numerouscharacteristics in combination. One skilled in the art will expedientlyconsider the characteristics individually as well and put them togetherto make appropriate further combination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1, a perspective view of a bearing housing;

FIG. 2, a perspective view of a partly mounted wiper bearing;

FIG. 3, a fragmentary longitudinal section through the wiper bearingwith a one-piece uncoupling element, taken along the line III—III inFIG. 2; and

FIG. 4, a variant of FIG. 3 with a two-piece uncoupling element.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A wiper bearing of a windshield wiper system is secured to a firewall 12of a vehicle body. It has a bearing housing 10, in which a drive shaft26 of a windshield wiper, not shown in further detail, is supported. Itis driven by a wiper motor via a lever gear, whose crank 14 is solidlyconnected to the end of the drive shaft remote from the windshield wiper(FIG. 2).

FIG. 1 shows the bearing housing 10, which is engaged by a force 16,introduced from the crank 14, along a longitudinal axis 18 of thebearing housing 10. For bracing against moment and transmitting forceinto the vehicle body, the bearing housing 10 has three bracing regions20, 22 and 24, whose spacings from one another are relatively great.

The first bracing region 20 is formed by a flange 30, which isintegrally cast onto the bearing housing 10, on an end toward the wiper.A second bracing region 22 and a third bracing region 24 form theplug-in feet 32 and 34, which are integrally cast, with an offset alongthe longitudinal axis 18, onto the crank end of the bearing housing 10.The plug-in feet 32 and 34 are disposed at a spacing [38], approximatelydiametrically to the longitudinal axis 18, from one another and arelocated in the same plane 36, which extends with a slight inclination tothe longitudinal axis 18 of the bearing housing 10.

Advantageously the plug-in feet 32 and 34 are connected to the bearinghousing 10 by a plurality of struts 40, so that while less material isconsumed, there is still a sufficiently great resistance to torsion andbending. The plug-in feet also have the form of a parallelepiped, whoseside faces 54 and 56 serve as receiving and guide faces. The end face 44and a guide face 42, formed onto the other face end, of the plug-in feet32 and 34 reinforce the side faces 54, 56 in the force and momentbracing process. They also form a stop for rubber-elastic uncouplingelements 46 and 48 slipped onto them, which uncoupling elements have acorresponding recess 50. As an alternative and simplified version, theseuncoupling elements could be replaced by integrally extruded uncouplingelements.

According to the invention, the bearing housing 10 is a die-cast partand has an integrally extruded thread 28 on an end toward the wiper. Thebearing housing 10 is designed structurally for pressure casting in sucha way that from the plug-in feet 32 and 34 to the integrally extrudedthread 28, it tapers in the primary direction of unmolding.

In order to secure the bearing housing 10 to the firewall 12 of thevehicle body, the firewall 12 has a retaining angle bracket 60 with areceiving opening 58, into which the end toward the wiper of the bearinghousing 10 is inserted for insertion. Also on the firewall 12, pockets62 and 64 that are open on the bottom and toward the bearing axis asprovided (FIG. 2), into which the plug-in feet 32 and 34 slide uponmounting and in which they are then retained. The firewall 12 is madefrom die-cast material, and the retaining angle bracket 60 and thepockets 62 and 64 are integrally cast with it. The primary unmolding isexpediently done in the direction of the arrow 52 and is thus in themounting direction of the wiper bearing.

The bearing housing 10 with the slipped-on and/or integrally extrudedtype of uncoupling elements 46 and 48 is mounted in the direction of thearrow 52 in the retaining angle bracket 60 and the pockets 62 and 64. Tomake it easier to join the components together, these components aredesigned structurally such that the edges 38, facing one another, of thebearing housing 10 and/or of the retaining angle bracket 60 or pockets62 and 64 are rounded and/or chamfered as an aid in centering.

A the drive shaft 26 is also joined into the bearing housing 10 in thedirection of the arrow 52. It protrudes past the bearing housing 10 onthe end toward the wiper, on which end a wiper arm, not shown, can bemounted. In the preassembly, a rubber-elastic uncoupling element 70 canbe snapped into the receiving opening 58 of the retaining angle bracket60; this uncoupling element prevents both the transmission of vibrationfrom the bearing housing 10 to the vehicle body and corrosion betweenthe bearing housing 10 and the retaining angle bracket 60 (FIG. 3).

A further variant of the damping is shown in FIG. 4, where theuncoupling element comprises two parts 72 and 74. After the mounting hasbeen concluded, it is provided that a disk 66 is joined to the sidetoward the wiper of the uncoupling element 70 or 72, and that a nut 68is screwed onto the thread 28 and firmly restrains the bearing housing10 on the retaining angle bracket 60.

What is claimed is:
 1. A windshield wiper system, comprising at leastone wiper bearing securable to a body of a vehicle, said wiper bearinghaving a bearing housing having three bracing regions with at least onebracing region for securing said wiper bearing to the body of thevehicle, said bracing regions comprising a first bracing region whichincludes a longitudinal axis of said bearing housing and is provided onan end that is orientable toward a wiper, and a second bracing regionand a third bracing region which are provided axially offset towardanother end relative to said first bracing region and are disposedapproximately diametrically opposite to one another with regard to saidlongitudinal axis of said bearing housing.
 2. A windshield wiper systemas defined in claim 1, wherein said first bracing region is formed by aflange on said bearing housing, said second and third bracing regionsbeing formed by two plug-in feet which are formed onto said housingsubstantially transversely to said longitudinal axis, said bearinghousing having a retaining device with pockets engaged by said twoplug-in feet.
 3. A windshield wiper system as defined in claim 2,wherein said bearing housing has a thread integrally extruded onto it,said thread adjoining said flange outward in a longitudinal direction.4. A windshield wiper system as defined in claim 2, wherein said plug-infeet have substantially radially extending side faces and also stopfaces oriented transversely to said side faces.
 5. A windshield wipersystem as defined in claim 2, and further comprising a firewallprovidable on the vehicle body and having a retaining angle bracket witha receiving opening, said bearing housing having an end extending towardthe wiper and inserted in said opening, said retaining angle bracketalso having pockets for receiving said plug-in feet.
 6. A windshieldwiper system as defined in claim 5, wherein said angle bracket and saidpockets are integrally cast with said firewall.
 7. A windshield wipersystem as defined in claim 1, wherein said bearing housing has edgeswhich face one another and are shaped in a shape selected from the groupconsisting of rounding and chamfering as an aid in centering.
 8. Awindshield wiper system as defined in claim 5, wherein said retainingangle bracket has edges which face one another and are shaped in a shapeselected from the group consisting of rounding and chamfering as an aidin centering.
 9. A windshield wiper system as defined in claim 5,wherein said pockets have edges which face one another and are shaped ina shape selected from the group consisting of rounding and chamfering asan aid in centering.
 10. A windshield wiper system as defined in claim5, wherein said firewall is designed so that a primary direction of itsunmolding is opposite to a mounting direction of said wiper bearing. 11.A windshield wiper system as defined in claim 1, wherein said bearinghousing is designed so that its unmolding and mounting take place in asame primary direction.
 12. A windshield wiper system as defined inclaim 5, and further comprising rubber-elastic uncoupling elementsprovided between said bearing housing and said retaining angle bracket,and between said plug-in feet and said pockets.
 13. A windshield wipersystem as defined in claim 12; and further comprising uncouplingelements which are formed as elements selected from the group consistingof elements slipped onto said plug-in feet and extruded onto saidplug-in feet.
 14. A windshield wiper system as defined in claim 12; andfurther comprising uncoupling elements which are snapped into saidreceiving opening of said retaining angle bracket.
 15. A windshieldwiper system as defined in claim 12; and further comprising uncouplingelement provided for said receiving opening of said retaining anglebracket and composed of two parts.